Free floating patient interface for laser surgery system

ABSTRACT

Systems and methods here may be used to support a laser eye surgery device, including a base assembly mounted to an optical scanning assembly via, a horizontal x axis bearing, a horizontal y axis bearing, and a vertical z axis bearing, mounted on the base assembly, configured to limit movement of the optical scanning assembly in an x axis, y axis and z axis respectively, relative to the base assembly, a vertical z axis spring, configured to counteract the forces of gravity on the optical scanning assembly in the z axis, and, mirrors mounted on the base assembly and positioned to reflect an energy beam into the optical scanning assembly no matter where the optical scanning assembly is located on the x axis bearing, the y axis bearing and the z axis bearing.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to and is a divisional of U.S. patent application Ser. No. 15/173,469, filed Jun. 3, 2016, issued as U.S. Pat. No. 10,470,932, which claims the benefit of priority as a Continuation-in-Part to U.S. application Ser. No. 14/190,827, titled Free Floating Patient Interface for Laser Surgery System, filed 26 Feb. 2014, issued as U.S. Pat. No. 10,751,217 (which in turn claims the benefit of priority to U.S. provisional application No. 61/780,881 filed on Mar. 13, 2013), as well as claims the benefit of priority as a Continuation-in-Part to U.S. application Ser. No. 14/575,884, titled Laser Eye Surgery System, filed 18 Dec. 2014, issued as U.S. Pat. No. 9,849,033, which claims the benefit of priority to U.S. application Ser. No. 14/191,095, titled Laser Eye Surgery System, filed 26 Feb. 2014, issued as U.S. Pat. No. 9,849,032 (which in turn claims the benefit of priority to U.S. Provisional Application Ser. No. 61/780,736 filed on Mar. 13, 2013), all of which applications are hereby incorporated by reference in their entirety.

BACKGROUND AND FIELD OF INVENTION

Laser eye surgery systems have become ubiquitous and varied in purpose. For example, a laser eye surgery system may be configured to reshape the anterior surface of the cornea via ablation to effect a refractive correction.

A laser eye surgery system may also be configured to create a corneal flap to expose an underlying portion of the cornea such that the underlying portion can be reshaped via ablation and then recovered with the flap. More recently-developed laser eye surgery systems may be configured to create one or more incisions in the cornea or limbus to reshape the cornea, create one or more incisions in the cornea to provide access for a cataract surgical instrument and/or to provide access for implantation of an intraocular lens, incise a capsulotomy in the anterior lens capsule to provide access for removal of a cataractous lens, segment a cataractous lens, and/or incise a capsulotomy in the posterior lens capsule opening.

Many laser eye surgery systems generate a series of laser beam pulses via a laser beam source. The laser beam pulses propagate along an optical path to the patient's eye. The optical path typically includes controllable elements such as scanning mechanisms and/or focusing mechanisms to control the direction and/or location of the emitted laser beam pulses relative to the patient.

Some laser eye surgery systems are configured to track eye movement (e.g., change of viewing direction of the eye) such that control over the direction and/or location of the emitted laser beam pulses can be accomplished so as to account for the eye movement. For example, a laser eye surgery system may optically track a feature in the eye, such as a natural feature or a fiduciary marker added to the eye, so as to track movement of the eye.

In contrast, other laser eye surgery systems may be configured to inhibit eye movement. For example, a contact lens may be employed that directly contacts the anterior surface of the cornea so as to restrain eye movement. Such restraint, however, may cause associated patient discomfort and/or anxiety.

Beyond eye movement, many laser eye surgery systems are configured to inhibit relative movement between the patient and the laser eye surgery system. For example, a laser eye surgery system may include some sort of substantial patient restraint feature such as a dedicated support assembly (e.g., chair or bed), which can include restraint features configured to inhibit movement of the patient relative to the support assembly. Such a dedicated support assembly may include a positioning mechanism by which the patient can be moved to suitably position the patient's eye relative to the optical path of the laser eye surgery system. Additionally, a laser eye surgery system may be configured to rigidly support components that determine the location of the optical path of the laser pulses so as to substantially prevent movement of the optical path relative to the dedicated support assembly, thereby also inhibiting relative movement of the patient's eye relative to the emitted laser pulses. A dedicated support assembly and rigid support of optical path components, however, can add significant complexity and related cost to a laser eye surgery system. Additionally, the use of rigid support of optical path components and a dedicated patient support assembly can fail to preclude the possibility of some level of significant relative movement between the patient and the laser eye surgery system.

Thus, laser surgery systems with improved characteristics with respect to patient movement, and related methods, may be beneficial.

SUMMARY

Accordingly, to obviate one or more problems due to limitations and disadvantages of the related art, this disclosure provides patient interface assemblies and related methods that can be used in suitable laser surgery systems such as, for example, laser eye surgery systems. In many embodiments, a patient interface assembly is configured to accommodate relative movement of a patient while maintaining alignment between a scanned electromagnetic treatment beam and the patient. By accommodating movement of the patient, additional system complexity and related cost associated with attempting to restrain movement of the patient can be avoided. Additionally, accommodation of movement of the patient can be employed to increase ease of use of a laser surgery system, such as by configuring the laser surgery system to be supported by a repositionable cart that can be moved adjacent to an existing patient support assembly (e.g., a non-dedicated patient support assembly such as a bed).

Thus, in one aspect, a method of accommodating patient movement in a laser surgery system is provided. The method includes using a first support assembly to support a scanner so as to accommodate relative translation between the scanner and the first support assembly parallel to a first direction. The scanner is operable to controllably scan an electromagnetic radiation beam and configured to be coupled with a patient so that the scanner moves in conjunction with movement of the patient. A second support assembly is used to support the first support assembly so as to accommodate relative translation between the first support assembly and the second support assembly parallel to a second direction that is transverse to the first direction. A base assembly is used to support the second support assembly so as to accommodate relative translation between the second support assembly and the base assembly parallel to a third direction that is transverse to each of the first and second directions. The electromagnetic radiation beam is propagated in a direction that is fixed relative to the base assembly. The first support assembly is used to support a first reflector configured to reflect the electromagnetic radiation beam so as to propagate parallel to the first direction and to the scanner. The second support assembly is used to support a second reflector configured to reflect the electromagnetic radiation beam so as to propagate parallel to the second direction and to be incident on the first reflector. Relative translation between the scanner and the first assembly, between the first assembly and the second assembly, and between the second assembly and the base assembly is used to accommodate three-dimensional relative translation between the scanner and the base assembly.

In many embodiments of the method, the scanner has particular operational characteristics relative to the electromagnetic radiation beam. For example, the scanner can be operable to scan the electromagnetic radiation beam in at least two dimensions. The scanner can be operable to focus the electromagnetic radiation beam to a focal point. The scanner can be operable to scan the focal point in three dimensions.

In many embodiments of the method, the second direction is perpendicular to the first direction and the third direction is perpendicular to each of the first and second directions. One of the first, second, and third directions can be vertically oriented. For example, the third direction can be vertically oriented and each of the first and second directions can be horizontally oriented. The method can include inhibiting at least one of (1) gravity-induced movement of the scanner in the vertical direction and (2) transfer of gravity-induced force to the patient.

In many embodiments of the method, the electromagnetic radiation beam includes a series of laser pulses. The laser pulses can be configured to modify eye tissue.

The method can include using the base assembly to support a third reflector. The third reflector can be configured to reflect the electromagnetic radiation beam to propagate parallel to the third direction and to be incident on the second reflector.

The method can include monitoring one or more relative positions between components. For example, the method can include monitoring a relative position of at least one of the group consisting of (1) between the scanner and the first support assembly, (2) between the first support assembly and the second support assembly, and (3) between the second support assembly and the base assembly.

The method can include inhibiting relative movement during positioning of the scanner relative to the patient between at least one of (1) the scanner and the first support assembly, (2) the first support assembly and the second support assembly, and (3) the second support assembly and the base assembly. Such inhibiting relative movement during positioning of the scanner relative to the patient can be used to ensure that adequate relative movement ranges are available after the scanner is positioned relative to the patient.

In another aspect, a patient interface assembly for a laser eye surgery system is provided. The patient interface assembly includes an eye interface device, a scanner, a first support assembly, a second support assembly, a base assembly, a beam source, a first reflector, and a second reflector. The eye interface is configured to interface with an eye of a patient. The scanner is coupled with the eye interface and operable to scan an electromagnetic radiation beam in at least two dimensions in an eye interfaced with the eye interface device. The scanner and the eye interface move in conjunction with movement of the eye. The first support assembly supports the scanner so as to accommodate relative translation between the scanner and the first support assembly parallel to a first direction. The second support assembly supports the first support assembly so as to accommodate relative translation between the first support assembly and the second support assembly parallel to a second direction that is transverse to the first direction. The base assembly supports the second support assembly so as to accommodate relative translation between the second support assembly and the base assembly parallel to a third direction. The third direction is transverse to each of the first and second directions. The beam source generates the electromagnetic radiation beam and outputs the electromagnetic radiation beam so as to propagate in a fixed direction relative to the base assembly. The first reflector is supported by the first support assembly and configured to reflect the electromagnetic radiation beam to propagate parallel to the first direction and propagate to the scanner. The second reflector is supported by the second support assembly and configured to reflect the electromagnetic radiation beam to propagate parallel to the second direction and to be incident on the first reflector. Relative translation between the scanner and the first assembly, between the first assembly and the second assembly, and between the second assembly and the base assembly accommodates three-dimensional relative translation between the eye interface and the base assembly.

The patient interface assembly can include an objective lens assembly disposed between the scanner and the eye interface. For example, the electromagnetic radiation beam can propagate from the scanner to pass through the objective lens assembly and then from the objective lens assembly through the eye interface.

In many embodiments of the patient interface assembly, the electromagnetic radiation beam is focused to a focal point. The scanner can be operable to scan the focal point in three dimensions in an eye interfaced with the eye interface device.

In many embodiments of the patient interface assembly, the scanner includes a z-scan device and an xy-scan device. The z-scan device can be operable to change a depth of the focal point in the eye. The xy-scan device can be operable to scan the focal point in two dimensions transverse to the propagation direction of the electromagnetic radiation beam.

In many embodiments of the patient interface assembly, the second direction is perpendicular to the first direction and the third direction is perpendicular to each of the first and second directions. One of the first, second, and third directions can be vertically oriented. The patient interface assembly can include a counter-balance mechanism coupled with the scanner and configured to inhibit at least one of (1) gravity-induced movement of the eye interface in the vertical direction and (2) transfer of gravity-induced force to an eye coupled with the eye interface device. The third direction can be vertically oriented and each of the first and second directions can be horizontally oriented.

The patient interface assembly can include at least one sensor to monitor relative position between components of the patient interface assembly. For example, the patient interface assembly can include at least one sensor configured to monitor relative position of at least one of the group consisting of between the scanner and the first support assembly, between the first support assembly and the second support assembly, and between the second support assembly and the base assembly.

In many embodiments of the patient interface assembly, the electromagnetic radiation beam includes a series of laser pulses. The laser pulses can be configured to modify eye tissue.

The patient interface assembly can include at least one device (e.g., one or more solenoid brake assemblies, one or more detent mechanisms, or any other suitable mechanism configured to selectively inhibit relative movement between components coupled for relative movement) configured to inhibit relative movement during positioning of the scanner relative to the patient between at least one of (1) the scanner and the first support assembly, (2) the first support assembly and the second support assembly, and (3) the second support assembly and the base assembly. Such a device(s) can be used to ensure that adequate relative movement ranges are available after the scanner is positioned relative to the patient.

In many embodiments, the patient interface assembly includes a third reflector supported by the base assembly. The third reflector is configured to reflect the electromagnetic radiation beam to propagate parallel to the third direction and to be incident on the second reflector.

In another aspect, a method of accommodating patient movement in a laser surgery system is provided. The method includes using a using a first support assembly to support a scanner so as to accommodate relative movement between the scanner and the first support assembly so as to accommodate patient movement. The scanner is operable to controllably scan an electromagnetic radiation beam and configured to be coupled with a patient so that the scanner moves in conjunction with movement of the patient. The method further includes using a beam source to generate the electromagnetic radiation beam. The method further includes propagating the electromagnetic radiation beam from the beam source to the scanner along an optical path having an optical path length that changes in response to patient movement.

The method can include further acts related to the optical path. For example, the method can include using a second support assembly to support the first support assembly so as to accommodate relative movement between the first support assembly and the second support assembly so as to accommodate patient movement. The method can include using the first support assembly to support a first reflector configured to reflect the electromagnetic radiation beam so as to propagate to the scanner along a portion of the optical path. The method can include using a base assembly to support the second support assembly so as to accommodate relative movement between the second support assembly and the base assembly so as to accommodate patient movement. The method can include using the second support assembly to support a second reflector configured to reflect the electromagnetic radiation beam to propagate along a portion of the optical path so as to be incident on the first reflector. The method can include using the base assembly to support a third reflector configured to reflect the electromagnetic radiation beam to propagate along a portion of the optical path so as to be incident on the second reflector.

The method can include the use of relative translation and/or relative rotation between optical path related components. For example, the relative movement between the scanner and the first support assembly can be a translation in a first direction. The relative movement between the first support assembly and the second support assembly can be a translation in a second direction that is transverse to the first direction. The relative movement between the second support assembly and the base assembly can be a translation in a third direction that is transverse to each of the first and second directions. The second direction can be perpendicular to the first direction. The third direction can be perpendicular to each of the first and second directions. At least one of (1) the relative movement between the scanner and the first support assembly, (2) the relative movement between the first support assembly and the second support assembly, and (3) the relative movement between the second support assembly and the base assembly can be a relative rotation.

The method can include inhibiting at least one of (1) gravity-induced movement of the scanner in the vertical direction and (2) transfer of gravity-induced force to the patient. One of the first, second, and third directions can be vertically oriented. For example, the third direction can be vertically oriented and each of the first and second directions can be horizontally oriented.

The scanner can be operable to scan any suitable electromagnetic radiation beam in any suitable fashion. For example, the scanner can be operable to scan the electromagnetic radiation beam in at least two dimensions. The scanner can be operable to focus the electromagnetic radiation beam to a focal point and scan the focal point in three dimensions. The scanner can be configured to be coupled with an eye of the patient and to controllably scan a focal point of the electromagnetic radiation beam within a tissue of the eye. The electromagnetic radiation beam can include a series of laser pulses configured to modify eye tissue.

The method can include monitoring relative position and/or relative orientation between optical path related components. For example, the method can include monitoring at least one of a relative position and a relative orientation of at least one of the group consisting of (1) between the scanner and the first support assembly, (2) between the first support assembly and the second support assembly, and (3) between the second support assembly and the base assembly.

The method can include inhibiting relative movement between optical path related components during positioning of the scanner relative to the patient. For example, the method can include inhibiting relative movement during positioning of the scanner relative to the patient between at least one of (1) the scanner and the first support assembly, (2) the first support assembly and the second support assembly, and (3) the second support assembly and the base assembly.

In another aspect, a patient interface assembly for a laser eye surgery system is provided. The patient interface assembly includes an eye interface device, a scanner, a first support assembly, and beam source. The eye interface device is configured to interface with an eye of a patient. The scanner is configured to be coupled with the eye interface device and operable to scan an electromagnetic radiation beam in at least two dimensions in an eye interfaced with the eye interface device. The scanner and the eye interface device move in conjunction with movement of the eye. The first support assembly supports the scanner so as to accommodate relative movement between the scanner and the first support assembly parallel so as to accommodate movement of the eye. The beam source generates the electromagnetic radiation beam. The electromagnetic radiation beam propagates from the beam source to the scanner along an optical path having an optical path length that varies in response to movement of the eye.

The patient interface assembly can include additional optical path related components. For example, the patient interface assembly can include a second support assembly that supports the first support assembly so as to accommodate relative movement between the first support assembly and the second support assembly so as to accommodate movement of the eye. The patient interface assembly can include a first reflector supported by the first support assembly and configured to reflect the electromagnetic radiation beam to propagate to the scanner along a portion of the optical path. The patient interface assembly can include a base assembly that supports the second support assembly so as to accommodate relative movement between the second support assembly and the base assembly so as to accommodate movement of the eye. The patient interface assembly can include a second reflector supported by the second support assembly and configured to reflect the electromagnetic radiation beam to propagate along a portion of the optical path so as to be incident on the first reflector. The patient interface assembly can include a third reflector supported by the base assembly and configured to reflect the electromagnetic radiation beam to propagate along a portion of the optical path so as to be incident on the second reflector.

The patient interface assembly can employ relative translation and/or relative rotation between optical path related components. For example, the relative movement between the scanner and the first support assembly can be a translation in a first direction. The relative movement between the first support assembly and the second support assembly can be a translation in a second direction that is transverse to the first direction. The relative movement between the second support assembly and the base assembly can be a translation in a third direction that is transverse to each of the first and second directions. The second direction can be perpendicular to the first direction. The third direction can be perpendicular to each of the first and second directions. At least one of (1) the relative movement between the scanner and the first support assembly, (2) the relative movement between the first support assembly and the second support assembly, and (3) the relative movement between the second support assembly and the base assembly can be a relative rotation.

The patient interface assembly can include a counter-balance mechanism configured to inhibit at least one of (1) gravity-induced movement of the scanner in the vertical direction and (2) transfer of gravity-induced force to eye of the patient. The third direction can be vertically oriented and each of the first and second directions can be horizontally oriented.

The scanner of the patient interface assembly can be operable to scan any suitable electromagnetic radiation beam in any suitable fashion. For example, the scanner can be operable to scan the electromagnetic radiation beam in at least two dimensions. The scanner can be operable to focus the electromagnetic radiation beam to a focal point and scan the focal point in three dimensions. The scanner can be configured to be coupled with an eye of the patient and to controllably scan a focal point of the electromagnetic radiation beam within a tissue of the eye. The electromagnetic radiation beam can include a series of laser pulses configured to modify eye tissue. The scanner can include a z-scan device and an xy-scan device. The z-scan device can be operable to change a depth of the focal point in the eye. The xy-scan device can be operable to scan the focal point in two dimensions transverse to the propagation direction of the electromagnetic radiation beam.

The patient interface assembly can include other suitable optical path related components. For example, the patient interface assembly can include at least one sensor configured to monitor relative position of at least one of the group consisting of (1) between the scanner and the first support assembly, (2) between the first support assembly and the second support assembly, and (3) between the second support assembly and the base assembly. The patient interface assembly can include an objective lens assembly disposed between and coupled with the scanner and the eye interface device. The electromagnetic radiation beam can propagate from the scanner to pass through the objective lens assembly and then from the objective lens assembly through the eye interface device. The patient interface assembly can include at least one device (e.g., one or more solenoid brake assemblies, one or more detent mechanisms, or any other suitable mechanism configured to selectively inhibit relative movement between components coupled for relative movement) configured to inhibit relative movement during positioning of the scanner relative to the patient between at least one of (1) the scanner and the first support assembly, (2) the first support assembly and the second support assembly, and (3) the second support assembly and the base assembly. Such a device(s) can be used to ensure that adequate relative movement ranges are available after the scanner is positioned relative to the patient.

For a fuller understanding of the nature and advantages of the present invention, reference should be made to the ensuing detailed description and accompanying drawings. Other aspects, objects and advantages of the invention will be apparent from the drawings and detailed description that follows.

This summary and the following detailed description are merely exemplary, illustrative, and explanatory, and are not intended to limit, but to provide further explanation of the invention as claimed. Additional features and advantages of the invention will be set forth in the descriptions that follow, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description, claims and the appended drawings.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

FIG. 1 is a schematic diagram of a laser surgery system, in accordance with many embodiments, in which a patient interface device is coupled to a laser assembly by way of a scanner and free-floating mechanism that supports the scanner.

FIG. 2 shows an isometric view of a patient interface assembly, in accordance with many embodiments, that includes a scanner supported by a free-floating mechanism.

FIG. 3 is a simplified block diagram of acts of a method, in accordance with many embodiments, for accommodating patient movement in a laser surgery system.

FIG. 4 is a simplified block diagram of optional acts, in accordance with many embodiments, that can be accomplished in the method of FIG. 3 .

FIG. 5 schematically illustrates relative movements that can be used in a patient interface assembly, in accordance with many embodiments, that includes a scanner supported by a free-floating mechanism.

FIG. 6A is a simplified block diagram of acts of another method, in accordance with many embodiments, for accommodating patient movement in a laser surgery system.

FIG. 6B is a simplified block diagram of optional acts, in accordance with many embodiments, that can be accomplished in the method of FIG. 6A.

FIG. 7 is a schematic diagram of a laser surgery system, in accordance with many embodiments, in which an eye interface device is coupled to a laser assembly by way of a scanner and free-floating mechanism that supports the scanner.

FIG. 8 is a schematic diagram of another laser surgery system, in accordance with many embodiments, in which an eye interface device is coupled to a laser assembly by way of a scanner and free-floating mechanism that supports the scanner.

FIG. 9 is another schematic diagram of the laser surgery system, in accordance with many embodiments, in which an eye interface device is coupled to a laser assembly by way of a scanner and free-floating mechanism that supports the scanner.

DETAILED DESCRIPTION

In the following description, various embodiments of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. It will also, however, be apparent to one skilled in the art that the present invention may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the embodiment being described.

The drawings and related descriptions of the embodiments have been simplified to illustrate elements that are relevant for a clear understanding of these embodiments, while eliminating various other elements found in conventional laser eye surgery systems. Those of ordinary skill in the art may thus recognize that other elements and/or steps are desirable and/or required in implementing the embodiments that are claimed and described. But, because those other elements and steps are well-known in the art, and because they do not necessarily facilitate a better understanding of the embodiments, they are not discussed. This disclosure is directed to all applicable variations, modifications, changes, and implementations known to those skilled in the art. As such, the following detailed descriptions are merely illustrative and exemplary in nature and are not intended to limit the embodiments of the subject matter or the uses of such embodiments. As used in this application, the terms “exemplary” and “illustrative” mean “serving as an example, instance, or illustration.” Any implementation described as exemplary or illustrative is not meant to be construed as preferred or advantageous over other implementations. Further, there is no intention to be bound by any expressed or implied theory presented in the preceding background, brief summary, or the following detailed description.

Patient interface assemblies and related methods for use in laser surgery systems are provided. While described herein as used in laser eye surgery systems, the patient interface assemblies and methods described herein can be used in any other suitable laser surgery system. In many embodiments, a free-floating patient interface assembly is configured to accommodate movement of a patient relative to the laser surgery system while maintaining alignment between an electromagnetic treatment beam emitted by the laser surgery system and the patient.

Referring now to the drawings in which like numbers reference similar elements, FIG. 1 schematically illustrates a laser surgery system 10, in accordance with many embodiments. The laser surgery system 10 includes a laser assembly 12, a free-floating mechanism 14, a scanning assembly 16, an objective lens assembly 18, and a patient interface device 20. The patient interface device 20 is configured to interface with a patient 22. The patient interface device 20 is supported by the objective lens assembly 18. The objective lens assembly 18 is supported by the scanning assembly 16. The scanning assembly 16 is supported by the free-floating mechanism 14. The free-floating mechanism 14 has a portion having a fixed position and orientation relative to the laser assembly 12.

In many embodiments, the patient interface device 20 is configured to interface with an eye of the patient 22. For example, the patient interface device 20 can be configured to be vacuum coupled to an eye of the patient 22 such as described in U.S. Publication No. US 2014-0128821 A1 (U.S. patent application Ser. No. 14/068,994, entitled “Liquid Optical Interface for Laser Eye Surgery System”, filed Oct. 31, 2013). The laser surgery system 10 can further optionally include a base assembly 24 that can be fixed in place or repositionable. For example, the base assembly 24 can be supported by a support linkage that is configured to allow selective repositioning of the base assembly 24 relative to a patient and secure the base assembly 24 in a selected fixed position relative to the patient. Such a support linkage can be supported in any suitable manner such as, for example, by a fixed support base or by a movable cart that can be repositioned to a suitable location adjacent to a patient. In many embodiments, the support linkage includes setup joints with each setup joint being configured to permit selective articulation of the setup joint and can be selectively locked to prevent inadvertent articulation of the setup joint, thereby securing the base assembly 24 in a selected fixed position relative to the patient when the setup joints are locked.

Eye Interface Examples

Certain older methods to measure the force on the eye 22 of the patient interface device 20 utilized three load cells. The slow response time (approx. ½ sec.) made this less than effective for docking the patient to the system and monitoring the force during the procedure. Plus, the load cells were used both to precisely locate the patient interface and measure the force on the patient's eye. Hence the load cells were mounted in a statically indeterminate manner and as a result hysteresis was a problem. These flaws made the load cell assembly unsuitable as a monitor for patient safety.

In many embodiments, the force sensor here uses a microelectromechanical system (MEMS) device. It utilizes the piezo resistive properties of the silicon device to convert the applied load into an electrical signal in the range of tens of millivolts. By preloading the force sensor in compression, the force sensor assembly can measure an appropriate range of axial and lateral forces exerted on the patient's eye. This force sensor assembly separates the functions of load sensing and precisely locating the patient so that hysteresis is not an issue. The response time is on the order of tens of microseconds and can be used to accurately measure and monitor the forces on a patient's eye while docking and during the procedure. As an added benefit, the force sensors are packaged in low profile Surface Mount Technology (SMT) package so that the force sensor assembly is thinner than the original load cell assembly by approximately 8 mm, improving the clearance between the system and the patient. The force sensor assembly has been designed to limit the load that can be applied to the force sensor effectively preventing an overload condition from ever occurring.

Laser Assembly Examples

In many embodiments, the laser assembly 12 is configured to emit an electromagnetic radiation beam 26. The beam 26 can include a series of laser pulses of any suitable energy level, duration, and repetition rate.

In many embodiments, the laser assembly 12 incorporates femtosecond (FS) laser technology. By using femtosecond laser technology, a short duration (e.g., approximately 10⁻¹³ seconds in duration) laser pulse (with energy level in the micro joule range) can be delivered to a tightly focused point to disrupt tissue, thereby substantially lowering the energy level required as compared to laser pulses having longer durations.

The laser assembly 12 can produce laser pulses having a wavelength suitable to treat and/or image tissue. For example, the laser assembly 12 can be configured to emit an electromagnetic radiation beam 26 such as emitted by any of the laser surgery systems described in U.S. Publication Nos. US 2014-0163534 A1 and US 2011-0172649 A1 (co-pending U.S. patent application Ser. No. 14/069,042, entitled “Laser Eye Surgery System”, filed Oct. 31, 2013; U.S. patent application Ser. No. 12/987,069, entitled “Method and System For Modifying Eye Tissue and Intraocular Lenses”, filed Jan. 7, 2011). For example, the laser assembly 12 can produce laser pulses having a wavelength from 1020 nm to 1050 nm. For example, the laser assembly 12 can have a diode-pumped solid-state configuration with a 1030 (+/−5) nm center wavelength. As another example, the laser assembly 12 can produce laser pulses having a wavelength 320 nm to 430 nm. For example, the laser assembly 12 can include an Nd:YAG laser source operating at the 3rd harmonic wavelength, 355 nm. The laser assembly 12 can also include two or more lasers of any suitable configuration.

The laser assembly 12 can include control and conditioning components. For example, such control components can include components such as a beam attenuator to control the energy of the laser pulse and the average power of the pulse train, a fixed aperture to control the cross-sectional spatial extent of the beam containing the laser pulses, one or more power monitors to monitor the flux and repetition rate of the beam train and therefore the energy of the laser pulses, and a shutter to allow/block transmission of the laser pulses. Such conditioning components can include an adjustable zoom assembly and a fixed optical relay to transfer the laser pulses over a distance while accommodating laser pulse beam positional and/or directional variability, thereby providing increased tolerance for component variation.

In many embodiments, the laser assembly 12 has a fixed position relative to the base assembly 24. The beam 26 emitted by the laser assembly 12 propagates along a fixed optical path to the free-floating mechanism 14. The beam 12 propagates through the free-floating mechanism 14 along a variable optical path 28, which delivers the beam 26 to the scanning assembly 16. In many embodiments, the beam 26 emitted by the laser assembly 12 is collimated so that the beam 26 is not impacted by patient movement induced changes in the length of the optical path between the laser assembly 12 and the scanning assembly 16. The scanning assembly 16 is operable to scan the beam 26 (e.g., via controlled variable deflection of the beam 26) in at least one dimension. In many embodiments, the scanner is operable to scan the beam in two dimensions transverse to the direction of propagation of the beam 26 and is further operable to scan the location of a focal point of the beam 26 in the direction of propagation of the beam 26. The scanned beam is emitted from the scanning assembly 16 to propagate through the objective lens assembly 18, through the interface device 20, and to the patient 22.

The free-floating mechanism 14 is configured to accommodate a range of movement of the patient 22 relative to the laser assembly 12 in one or more directions while maintaining alignment of the beam 24 emitted by the scanning assembly 16 with the patient 22. For example, in many embodiments, the free-floating mechanism 14 is configured to accommodate a range movement of the patient 22 in any direction defined by any combination of unit orthogonal directions (X, Y, and Z).

The free-floating mechanism 14 supports the scanning assembly 16 and provides the variable optical path 28, which changes in response to movement of the patient 22. Because the patient interface device 20 is interfaced with the patient 22, movement of the patient 22 results in corresponding movement of the patient interface device 20, the objective lens assembly 18, and the scanning assembly 16. The free-floating mechanism 14 can include, for example, any suitable combination of a linkage that accommodates relative movement between the scanning assembly 16 and the laser assembly 12 and optical components suitably tied to the linkage so as to form the variable optical path 28.

FIG. 2 shows an free floating assembly 16 to illustrate an example embodiment of a suitable combination of a linkage that accommodates relative movement between the scanning assembly 16 and the laser assembly 12 and optical components suitably tied to the linkage so as to form the variable optical path 28. The free floating assembly 16 includes an eye interface device 20, the objective lens assembly 18, the scanning assembly 16, and the free-floating mechanism 14. The free-floating mechanism 14 includes a first support assembly 32, a second support assembly 34, and a base assembly 36. The eye interface device 20 is coupled with and supported by the objective lens assembly 18. The objective lens assembly 18 is coupled with and supported by the scanning assembly 16. The combination of the interface device 20, the objective lens assembly 18, and the scanning assembly 16 form a unit that moves in unison in conjunction with movement of the patient.

The first support assembly 32 includes a first end frame 38, a second end frame 40, and transverse rods 42, 44, which extend between and couple to the end frames 38, 40. The transverse rods 42, 44 are oriented parallel to a first direction 46. The scanning assembly 16 is supported by the transverse rods 42, 44 and slides along the rods 42, 44 in response to patient movement parallel to the first direction 46. The transverse rods 42, 44 form part of a linear bearing accommodating patient movement parallel to the first direction 46.

The second support assembly 34 includes a first end frame 48, an intermediate frame 50, transverse rods 52, 54, a second end frame 56, and vertical rods 58, 60. The transverse rods 52, 54 extend between and couple to the first end frame 48 and to the intermediate frame 50. The transverse rods 52, 54 are oriented parallel to a second direction 62, which is at least transverse to and can be orthogonal to the first direction 46. Each of the first and second directions 46, 62 can be horizontal. The first support assembly 32 is supported by the transverse rods 52, 54 and slides along the rods 52, 54 in response to patient movement parallel to the second direction 62. The transverse rods 52, 54 form part of a linear bearing accommodating patient movement parallel to the second direction 62. The vertical rods 58, 60 extend between and couple to the intermediate frame 50 and to the second end frame 56. The vertical rods 58, 60 are oriented parallel to a third direction 64, which is at least transverse to each of first and second directions 46, 62, and can be orthogonal to at least one of the first and second directions 46, 62. The vertical rods 58, 60 form part of a linear bearing accommodating relative movement between the second support assembly 34 and the base assembly 36 parallel to the third direction 64, thereby accommodating patient movement parallel to the third direction 64.

First, second, and third reflectors 66, 68, 70 (e.g., mirrors) are supported by the free-floating mechanism 14 and configured to reflect the electromagnetic radiation beam 26 to propagate along a variable optical path 28. The first reflector 66 is mounted to the first support assembly 32 (to second end frame 42 in the illustrated embodiment). The second reflector 68 is mounted to the second support assembly 34 (to intermediate frame 50 in the illustrated embodiment). The third reflector 70 is mounted to the base assembly 36. In operation, the beam 26 emitted by the laser assembly is deflected by the third reflector 70 so as to propagate parallel to the third direction 64 and be incident upon the second reflector 68. The second reflector 68 deflects the beam 26 so as to propagate parallel to the second direction 62 and be incident upon the first reflector 66. The first reflector 66 deflects the beam 26 so as to propagate parallel to the first direction 46 and into the scanning assembly 16, which then controllably scans and outputs the scanned beam through the objective lens assembly 18 and the eye interface device 20. By propagating the beam 26 parallel to the third direction 64 from the third reflector 70 to the second reflector 68, the length of the corresponding portion of the variable optical path 28 can be varied so as to accommodate relative movement of the patient relative to the third direction 64. By propagating the beam 26 parallel to the second direction 62 from the second reflector 68 to the first reflector 66, the length of the corresponding portion of the variable optical path 28 can be varied so as to accommodate relative movement of the patient relative to the second direction 62. By propagating the beam 26 parallel to the first direction 46 from the first reflector 66 to the scanning assembly 16, the length of the corresponding portion of the variable optical path 28 can be varied so as to accommodate relative movement of the patient relative to the first direction 46.

In the illustrated embodiment, the free-floating mechanism 14 further includes a first solenoid brake assembly 72, a second solenoid brake assembly 74, and a third solenoid brake assembly 76. The solenoid brake assemblies 72, 74, 76 are operable to selectively prevent inadvertent articulation of the free-floating mechanism 14 during initial positioning of the scanning assembly 16 relative to a patient's eye. For example, in the absence of any mechanism for preventing inadvertent articulation of the free-floating mechanism 14, movement of the scanning assembly 16 may induce inadvertent articulation of the free-floating mechanism 14, especially when a user induces movement of the scanning assembly 16 through contact with, for example, the objective lens assembly 18 to move the objective lens assembly 18 into a suitable location relative to the patient. When the laser surgery system 10 is supported by a support linkage mechanism that includes setup joints, preventing inadvertent articulation of the free-floating mechanism 14 can be used to ensure that the initial positioning of the laser surgery system 10 occurs via articulation of the setup joints instead of via articulation of the free-floating mechanism 14.

The first solenoid brake assembly 72 is configured to selectively prevent inadvertent movement between the scanning assembly 16 and the first support assembly 32. Engagement of the first solenoid brake assembly 72 prevents movement of the scanning assembly 16 along the transverse rods 42, 44, thereby preventing relative movement between the scanning assembly 16 and the first support assembly 32 parallel to the first direction 46. When the first solenoid brake assembly 72 is not engaged, the scanning assembly 16 is free to slide along the transverse rods 42, 44, thereby permitting relative movement between the scanning assembly 16 and the first support assembly 32 parallel to the first direction 46. In many embodiments, the free-floating mechanism 14 includes a detent mechanism and/or an indicator that is configured to permit engagement of the first solenoid brake assembly 72 when the scanning assembly 16 is centered relative to its range of travel along the transverse rods 42, 44, thereby ensuring equal range of travel of the scanning assembly 16 in both directions parallel to the first direction 46 when the first solenoid brake assembly 72 is disengaged following positioning of the objective lens assembly 18 relative to the patient.

The second solenoid brake assembly 74 is configured to selectively prevent inadvertent movement between the first support assembly 32 and the second support assembly 34. Engagement of the second solenoid brake assembly 74 prevents movement of the first support assembly 32 along the transverse rods 52, 54, thereby preventing relative movement between the first support assembly 32 and the second support assembly 34 parallel to the second direction 62. When the second solenoid brake assembly 74 is not engaged, the first support assembly 32 is free to slide along the transverse rods 52, 54, thereby permitting relative movement between the first support assembly 32 and the second support assembly 34 parallel to the second direction 62. In many embodiments, the free-floating mechanism 14 includes a detent mechanism and/or an indicator that is configured to permit engagement of the second solenoid brake assembly 74 when the first support assembly 32 is centered relative to its range of travel along the transverse rods 52, 54, thereby ensuring equal range of travel of the first support assembly 32 in both directions parallel to the second direction 62 when the second solenoid brake assembly 74 is disengaged following positioning of the objective lens assembly 18 relative to the patient.

The third solenoid brake assembly 76 is configured to selectively prevent inadvertent movement between the second support assembly 34 and the base assembly 36. Engagement of the third solenoid brake assembly 76 prevents movement of the base assembly 36 along the vertical rods 58, 60, thereby preventing relative movement between the second support assembly 34 and the base assembly 36 parallel to the third direction 64. When the third solenoid brake assembly 76 is not engaged, the base assembly 36 is free to slide along the vertical rods 58, 60, thereby permitting relative movement between the second support assembly 34 and the base assembly 36 parallel to the third direction 64. In many embodiments, the free-floating mechanism 14 includes a detent mechanism and/or an indicator that is configured to permit engagement of the third solenoid brake assembly 76 when the base assembly 36 is centered relative to its range of travel along the vertical rods 58, 60, thereby ensuring equal range of travel of the base assembly 36 in both directions parallel to the third direction 64 when the third solenoid brake assembly 76 is disengaged following positioning of the objective lens assembly 18 relative to the patient.

In an optional embodiment, the third reflector 70 is omitted and the incoming beam 26 is directed to propagate parallel to the third direction 64 and be incident on the second reflector 68. Each of the reflectors 66, 68, 70 can be adjustable in position and/or in orientation and thereby can be adjusted to align the corresponding portions of the variable optical path 28 with the first, second, and third directions 46, 62, and 64, respectively. Accordingly, the use of the third reflector 70 can provide the ability to align the portion of the variable optical path 28 between the third reflector 70 and the second reflector 68 so as to be parallel to the third direction 64 and thereby compensate for relative positional and/or orientation variability between the laser assembly 12 and the free-floating mechanism 14.

In the illustrated embodiment of the free floating assembly 16, the first and second directions 46, 62 can be horizontal and the third direction 64 can be vertical. The free-floating mechanism 14 can also include a counter-balance mechanism coupled with the scanner and configured to inhibit gravity-induced movement of the eye interface device 20 and/or inhibit the transfer of gravity-induced forces from the eye interface device 20 to an eye coupled with the eye interface device 20. For example, a counter-balance mechanism can be employed to apply a counter-balancing vertical force to the second assembly 34, thereby inhibiting or even preventing gravity-induced relative movement between the second assembly 34 and the base assembly 36 and/or inhibiting the transfer of gravity-induced forces from the eye interface device 20 to an eye coupled with the eye interface device 20.

Other suitable variations of the free floating assembly 16 are possible. For example, the scanning assembly 16 can be slidably supported relative to a first support assembly via a vertically-oriented linear bearing. The first support assembly can be slidably supported relative to a second support assembly via a first horizontally-oriented linear bearing. The second support assembly can be slidably supported relative to a base assembly via a second horizontally-oriented linear bearing that is oriented transverse (e.g., perpendicular) to the first horizontally-oriented linear bearing. In such a configuration, a counter-balancing mechanism can be used to apply a counter-balancing force to the scanning assembly 16, thereby inhibiting or even preventing gravity-induced relative movement of the scanning assembly 16 and the eye interface device 20 and/or inhibiting or even preventing the transfer of gravity-induced force from the eye interface device 20 to an eye coupled with the eye interface device 20. The free floating assembly 16 can also incorporate one or more sensors configured to monitor relative position 1) between the scanning assembly 16 and the first support assembly 32, 2) between the first support assembly 32 and the second support assembly 34, and/or 3) between the second support assembly 34 and the base assembly 36.

FIG. 3 is a simplified block diagram of acts of a method 100, in accordance with many embodiments, of accommodating patient movement in a laser surgery system. Any suitable device, assembly, and/or system described herein can be used to practice the method 100. The method 100 includes using a first support assembly (e.g., first support assembly 32) to support a scanner (e.g., scanning assembly 16) so as to accommodate relative translation between the scanner and the first support assembly parallel to a first direction (e.g., direction 46). The scanner is operable to controllably scan an electromagnetic radiation beam (e.g., beam 26) and configured to be coupled with a patient so that the scanner moves in conjunction with movement of the patient (act 102). A second support assembly (e.g., second support assembly 34) is used to support the first support assembly so as to accommodate relative translation between the first support assembly and the second support assembly parallel to a second direction (e.g., direction 62) that is transverse to the first direction (act 104). A base assembly (e.g., base assembly 36) is used to support the second support assembly so as to accommodate relative translation between the second support assembly and the base assembly parallel to a third direction (e.g., direction 64) that is transverse to each of the first and second directions (act 106). The electromagnetic radiation beam is propagated in a direction that is fixed relative to the base assembly (act 108). The first support assembly is used to support a first reflector (e.g., first reflector 66) configured to reflect the electromagnetic radiation beam so as to propagate parallel to the first direction and to the scanner (act 110). The second support assembly is used to support a second reflector (e.g., second reflector 68) configured to reflect the electromagnetic radiation beam so as to propagate parallel to the second direction and to be incident on the first reflector (act 112). Relative translation between the scanner and the first assembly, between the first assembly and the second assembly, and between the second assembly and the base assembly is used to accommodate three-dimensional relative translation between the scanner and the base assembly (act 114).

FIG. 4 is a simplified block diagram of additional aspects and/or optional acts that can be accomplished as part of the method 100. For example, the method 100 can include using the base assembly to support a third reflector (e.g., third reflector 70) configured to reflect the electromagnetic radiation beam to propagate parallel to the third direction and to be incident on the second reflector (act 116). The method 100 can include operating the scanner to scan the electromagnetic radiation beam in at least two dimensions (act 118). The method 100 can include focusing the electromagnetic radiation beam to a focal point (act 120). The method 100 can include operating the scanner to scan the focal point in three dimensions (act 122). The method 100 can include using a counter-balance mechanism to inhibit gravity-induced movement of the scanner and/or to inhibit transfer of gravity-induced force to an eye coupled with the scanner (act 124). The method 100 can include monitoring a relative position of at least one of the group consisting of (1) between the scanner and the first support assembly, (2) between the first support assembly and the second support assembly, and (3) between the second support assembly and the base assembly (act 126). The method 100 can include inhibiting relative movement during positioning of the scanner relative to the patient between at least one of (1) the scanner and the first support assembly, (2) the first support assembly and the second support assembly, and (3) the second support assembly and the base assembly (act 128).

FIG. 5 schematically illustrates relative movements that can be used in the free-floating mechanism 14 that can be used to accommodate patient movement, in accordance with many embodiments. The free-floating mechanism 14 includes the first reflector 66, the second reflector 68, and the third reflector 70. In many embodiments, the free-floating mechanism 14 includes a linkage assembly (not shown) that is configured to permit certain relative movement between the scanning assembly 16 and the first reflector 66, between the first reflector 66 and the second reflector 68, and between the second reflector 68 and the third reflector 70 so as to consistently direct the electromagnetic radiation beam 26 to the scanning assembly 16 while accommodating three-dimensional relative movement between the patient interface device 20 and the laser assembly used to generate the electromagnetic radiation beam 26. For example, similar to the embodiment of the free-floating mechanism 14 illustrated in FIG. 2 , a free-floating mechanism 14 can be configured such that the scanning assembly 16 is supported by a first support assembly such that the scanner is free to translate relative to the first support assembly parallel to the first direction 46, thereby maintaining the location and orientation of the beam 26 between the first reflector 66 and the scanning assembly 16. Likewise, the first support assembly can be supported by a second support assembly such that the first support assembly is free to translate relative to the second support assembly parallel to a second direction 62, thereby maintaining the location and orientation of the beam 26 between the second reflector 68 and the first reflector 66. And the second support assembly can be supported by a base assembly such that the second support assembly is free to translate relative to the base assembly parallel to a third direction 64, thereby maintaining the location and orientation of the beam 26 between the third reflector 70 and the second reflector 68.

The free-floating mechanism 14 can also employ one or more relative rotations so as to maintain the location and orientation of path segments of the beam 26. For example, the scanning assembly 16 can be supported by a first support assembly such that the scanner is free to undergo a rotation 78 relative to the first support assembly about an axis coincident with the path segment of the beam 26 between the first reflector 66 and the scanning assembly 16, thereby maintaining the location and orientation of the beam 26 between the first reflector 66 and the scanning assembly 16. Likewise, the first support assembly can be supported by a second support assembly such that the first support assembly is free to undergo a rotation 80 relative to the second support assembly about an axis coincident with the path segment of the beam 26 between the second reflector 68 and the first reflector 66, thereby maintaining the location and orientation of the beam 26 between the second reflector 68 and the first reflector 66. And the second support assembly can be supported by a base assembly such that the second support assembly is free to undergo a rotation 82 relative to the base assembly about an axis coincident with the path segment of the beam 26 between the third reflector 70 and the second reflector 68, thereby maintaining the location and orientation of the beam 26 between the third reflector 70 and the second reflector 68.

The free-floating mechanism 14 can also employ any suitable combination of relative translations and relative rotations so as to maintain the location and orientation of path segments of the beam 26. For example, with respect to the configuration illustrated in FIG. 5 , the free-floating mechanism 14 can employ relative translation parallel to the second direction 62, relative translation parallel to the third direction 64, and relative rotation 82, thereby allowing three-dimensional movement of the patient interface 20 relative to the laser assembly used to generate the electromagnetic radiation beam 26, and thereby accommodating patient movement.

FIG. 6A is a simplified block diagram of acts of a method 200, in accordance with many embodiments, of accommodating patient movement in a laser surgery system. Any suitable device, assembly, and/or system described herein can be used to practice the method 200. The method 200 includes using a first support assembly to support a scanner so as to accommodate relative movement between the scanner and the first support assembly so as to accommodate patient movement. The scanner is operable to controllably scan an electromagnetic radiation beam and configured to be coupled with a patient so that the scanner moves in conjunction with movement of the patient (act 202). The method 200 includes using a beam source to generate the electromagnetic radiation beam (act 204). The method 200 includes propagating the electromagnetic radiation beam from the beam source to the scanner along an optical path having an optical path length that changes in response to patient movement (act 206).

FIG. 6B is a simplified block diagram of additional aspects and/or optional acts that can be accomplished as part of the method 200. For example, the method 200 can include using a second support assembly to support the first support assembly so as to accommodate relative movement between the first support assembly and the second support assembly so as to accommodate patient movement (act 208). The method 200 can include using the first support assembly to support a first reflector configured to reflect the electromagnetic radiation beam so as to propagate to the scanner along a portion of the optical path (act 210). The method 200 can include using a base assembly to support the second support assembly so as to accommodate relative movement between the second support assembly and the base assembly so as to accommodate patient movement (act 212). The method 200 can include using the second support assembly to support a second reflector configured to reflect the electromagnetic radiation beam to propagate along a portion of the optical path so as to be incident on the first reflector (act 214). The method 200 can include using the base assembly to support a third reflector configured to reflect the electromagnetic radiation beam to propagate along a portion of the optical path so as to be incident on the second reflector (act 216). The method 200 can include monitoring at least one of a relative position and a relative orientation of at least one of the group consisting of (1) between the scanner and the first support assembly, (2) between the first support assembly and the second support assembly, and (3) between the second support assembly and the base assembly (act 218). The method 200 can include inhibiting relative movement during positioning of the scanner relative to the patient between at least one of (1) the scanner and the first support assembly, (2) the first support assembly and the second support assembly, and (3) the second support assembly and the base assembly (act 220).

FIG. 7 schematically illustrates a laser surgery system 300, in accordance with many embodiments. The laser surgery system 300 includes the laser assembly 12, the free-floating mechanism 14, the scanning assembly 16, the objective lens assembly 18, the patient interface 20, communication paths 302, control electronics 304, control panel/graphical user interface (GUI) 306, and user interface devices 308. The control electronics 304 includes processor 310, which includes memory 312. The patient interface 20 is configured to interface with a patient 22. The control electronics 304 is operatively coupled via the communication paths 302 with the laser assembly 12, the free-floating mechanism 14, the scanning assembly 16, the control panel/GUI 306, and the user interface devices 308.

The free-floating mechanism 14 can be configured as illustrated in FIG. 2 to include, for example, the first reflector 66, the second reflector 68, and the third reflector 70. Accordingly, the free-floating mechanism 14 can be configured to accommodate movement of the patient 22 relative to the laser assembly 12 in any direction resulting from any combination of three orthogonal unit directions.

The scanning assembly 16 includes a z-scan device 314 and an xy-scan device 316. The laser surgery system 300 is configured to focus the electromagnetic radiation beam 26 to a focal point that is scanned in three dimensions. The z-scan device 314 is operable to vary the location of the focal point in the direction of propagation of the beam 26. The xy-scan device 316 is operable to scan the location of the focal point in two dimensions transverse to the direction of propagation of the beam 26. Accordingly, the combination of the z-scan device 314 and the xy-scan device 316 can be operated to controllably scan the focal point of the beam in three dimensions, including within a tissue of the patient 22 such as within an eye tissue of the patient 22. As described above with respect to free floating assembly 16, the scanning assembly 16 is supported by the free-floating mechanism 14, which accommodates patient movement induced movement of the scanning device relative to the laser assembly 12 in three dimensions.

The patient interface 20 is coupled to the patient 22 such that the patient interface 20, the objective lens 18, and the scanning assembly 16 move in conjunction with the patient 22. For example, in many embodiments, the patient interface 20 employs a suction ring that is vacuum attached to an eye of the patient 20. The suction ring can be coupled with the patient interface 20, for example, using vacuum to secure the suction ring to the patient interface 20.

The control electronics 304 controls the operation of and/or can receive input from the laser assembly 12, the free-floating assembly 14, the scanning assembly 16, the patient interface 20, the control panel/GUI 306, and the user interface devices 308 via the communication paths 302. The communication paths 302 can be implemented in any suitable configuration, including any suitable shared or dedicated communication paths between the control electronics 304 and the respective system components.

The control electronics 304 can include any suitable components, such as one or more processor, one or more field-programmable gate array (FPGA), and one or more memory storage devices. In many embodiments, the control electronics 304 controls the control panel/GUI 306 to provide for pre-procedure planning according to user specified treatment parameters as well as to provide user control over the laser eye surgery procedure.

The control electronics 304 can include a processor/controller 310 that is used to perform calculations related to system operation and provide control signals to the various system elements. A computer readable medium 312 is coupled to the processor 310 in order to store data used by the processor and other system elements. The processor 310 interacts with the other components of the system as described more fully throughout the present specification. In an embodiment, the memory 312 can include a look up table that can be utilized to control one or more components of the laser system surgery system 300.

The processor 310 can be a general purpose microprocessor configured to execute instructions and data, such as a Pentium processor manufactured by the Intel Corporation of Santa Clara, Calif. It can also be an Application Specific Integrated Circuit (ASIC) that embodies at least part of the instructions for performing the method in accordance with the embodiments of the present disclosure in software, firmware and/or hardware. As an example, such processors include dedicated circuitry, ASICs, combinatorial logic, other programmable processors, combinations thereof, and the like.

The memory 312 can be local or distributed as appropriate to the particular application. Memory 312 can include a number of memories including a main random access memory (RAM) for storage of instructions and data during program execution and a read only memory (ROM) in which fixed instructions are stored. Thus, the memory 312 provides persistent (non-volatile) storage for program and data files, and may include a hard disk drive, flash memory, a floppy disk drive along with associated removable media, a Compact Disk Read Only Memory (CD-ROM) drive, an optical drive, removable media cartridges, and other like storage media.

The user interface devices 308 can include any suitable user input device suitable to provide user input to the control electronics 304. For example, the user interface devices 308 can include devices such as, for example, a touch-screen display/input device, a keyboard, a footswitch, a keypad, a patient interface radio frequency identification (RFID) reader, an emergency stop button, and a key switch.

Any suitable laser surgery system can be suitably modified to employ an electromagnetic beam scanner that is supported by a free-floating mechanism as disclosed herein. For example, co-pending U.S. provisional patent application Ser. No. 14/069,042 filed Oct. 31, 2013 (published as U.S. Publication No. US 2014-0163534 A1), describes a laser eye surgery system that includes beam scanning components that form part of a shared optical assembly used to scan a treatment beam, an optical coherence tomography (OCT) measurement beam, and an alignment beam. Using the approaches described herein, such beam scanning components can be supported from a free-floating mechanism so as to accommodate patient movement as described herein.

FIG. 8 is a schematic diagram of a laser surgery system, in accordance with many embodiments, in which an eye interface device is coupled to a laser assembly by way of a scanner and free-floating mechanism that supports the scanner. The mechanism shown in FIG. 8 could be used in lieu of the assembly shown in FIG. 2 , for example working in conjunction with the laser assembly 12 from FIG. 1 . Thus, FIG. 8 shows an assembly 400 example embodiment of a suitable combination of a linkage that accommodates relative movement between the scanning assembly 16 and the laser assembly 12 and optical components suitably tied to the linkage so as to form the variable optical path 28 (from FIG. 1 ). Such free-floating head mechanism could be used to move in unison with the movement of a patient.

FIG. 8 shows another example free-floating head mechanism assembly 400 with three degrees of freedom of movement about three axes x, y and z. Thus, the system includes a base assembly 410 upon which components are attached. The base assembly is stable relative to a floating scanning assembly 440 and objective lens assembly 420 which are attached to the base assembly 410 but are able to move in three degrees of freedom according to the embodiments described here.

The base assembly 410 is shown as a framework of parts that are arranged to support the components of the system here. The base assembly 410 could be made of any number of things including metal such as aluminum or steel, it could be made of plastics or composites, or a combination of things. The example base assembly 410 in FIG. 8 generally has two flat platforms 412 that are held apart by various struts 414. The example is not intended to be limiting and any arrangement of support structure could be used.

Regarding the relative motion of the floating scanning assembly 440 and objective lens assembly 420 relative to the base assembly 410, the first axis of movement is a z axis which is made possible using a z axis spring mechanism 430 and vertical z axis bearings 432. The z axis bearings 432 allow the floating scanning assembly 440 and objective lens assembly 420 to move vertically, up and down, relative to the base assembly 410.

Such a bearing system may include rollers and a linear track or rail system that keeps the floating scanning assembly 440 and objective lens assembly 420 from shifting off of a smooth and direct movement in any particular axis. In such an assembly, a roller, or multiple rollers are configured to contact a track or rail. Each of the two, the roller assembly and track, are attached to either the base assembly or the floating scanning assembly 440 and lens assembly 440. Thus, as the rollers and track interact, the floating scanning assembly 440 and lens assembly 440 movement, relative to the base assembly 410 is forced into a linear direction, according to the orientation of the bearing track, in this example, that is along the z axis. As discussed herein, a combination of such bearings, can allow for the floating scanning assembly 440 and lens assembly 440 to move about more than one axis and more than one degree of freedom, relative to the base assembly 410, depending on how many axes are configured.

It should be noted that the example of these roller and track bearings in FIG. 8 is merely exemplary and any kind of bearings could be used.

To complement the vertical bearings 432 in the example embodiment shown in FIG. 8 , a system of springs 430 are shown that help keep any vertical movement of the floating scanning assembly 440 and objective lens assembly 420 from happening unless acted upon by a force other than gravity, such as a user or operator positioning the floating scanning assembly 440 and objective lens assembly 420. In FIG. 8 , the example mechanism shown includes two z axis springs 430 but it should be noted that any arrangement of multiple or one spring could be used. These springs 430 can counteract the force of gravity, which accelerates the floating scanning assembly 440 and objective lens assembly 420 toward the earth. Thus, the z axis is the only axis that needs additional assistance to counteract gravity, hence the springs.

In the example embodiment in FIG. 8 , the z axis springs 430 are shown as metal tapes wound around spring loaded bearing spools. When the floating scanning assembly 440 and objective lens assembly 420 is moved by an outside force such as a user or operator in the vertical dimension, or z axis, the metal tapes coil or uncoil respectively and the spring tension within the coils keep the floating scanning assembly 440 and objective lens assembly 420 from free falling due to gravity. It should be noted that the wound tape spring example is not intended to be limiting. Any kind of spring mechanism or other mechanism could be used with similar effect. For example, a hydraulic piston system could be used to counteract gravity, a coiled wire spring system could be used, a pulley system could be used, a geared system could be used, a magnetic system could be used, etc. Additionally a locking mechanism could be used to hold the floating scanning assembly 440 and objective lens assembly 420 in place, relative to the base assembly, after it is positioned.

The free-floating head mechanism 400 also includes bearings in the horizontal x axis 434 and the horizontal y axis 436 as well as the z axis as discussed. Such x axis and y axis bearings keep the floating scanning assembly 440 and objective lens assembly 420 from slipping or shifting, relative to the base assembly 410, in the x and y axis directions. Used in combination, these bearings allow for the floating scanning assembly 440 and objective lens assembly 420 to move in a horizontal plane, for example.

It should be noted that the horizontal bearings do not necessarily include springs such as those used for the z axis because generally there is not a force acting upon the horizontal plane as there is in the vertical plane with gravity. But the bearings in any degree of freedom could include a brake or lock mechanism to keep the floating scanning assembly 440 and objective lens assembly 420 locked into a certain position, for any or all of the three axes. Such a brake could be a pin and hole, either spring loaded or not. A lock could be a gear mechanism with a latch that holds the gear. A lock could be a stopper on a spring or piston as well. It could be a solenoid brake, either manually operated or magnetically. Any of various locks could be used in any one or combination of the axes.

The combination of the three axis bearing arrangement as shown in FIG. 8 allows for the entire floating scanning assembly 440 and objective lens assembly 420 to be moved, by an operator or user, relative to the base assembly 410 in any position of the three axes: up and down, left and right, and in and out, and thus any position in three dimensional space, within the boundaries of the bearing tracks. Thus, the range of motion is only limited by the physical length of the bearing rails or tracks in each direction. If the z axis bearing rail or track has a total length of 12 inches, the range of motion of the floating scanning assembly 440 and objective lens assembly 420 relative to the base assembly 410 would be 12 inches. The x axis bearing could have the same length or different length. The y axis bearing could have the same length or different length. The combination of the three axis bearings would define the range of motion within the three degrees of freedom for the floating scanning assembly 440 and objective lens assembly 420. In combination, these three axes allow for the floating scanning assembly 440 and objective lens assembly 420 to be positioned in any three dimensional coordinate within the range of the system.

Referring now to FIG. 9 , the free-floating head mechanism 400 is depicted with the three axes of movement for the floating scanning assembly 440 and objective lens assembly 420 relative to the base assembly 410 from FIG. 8 , as shown with arrows. The vertical z axis 462, the horizontal y axis 466 and the horizontal x axis 464 are all shown which are the three axes in this example that the floating scanning assembly 440 and objective lens assembly 420 are able to move relative to the base assembly 410 from FIG. 8 .

It should be noted that the combination of the three axis system as described here is merely exemplary. Fewer axes could be used, or additional axes could be used. In certain example embodiments, additional axes of rotations could be added for example, with a rotating or pivoting bearing assembly or assemblies attached to the base assembly 410 as well. Such an embodiment is not shown, but could be configured to add one, two, or three more degrees of freedom to the movement of the assembly 400.

Certain example embodiments may include motors, attached to or in communication with the bearings. Such motors could actuate movement of the optical scanning module 440 and lens assembly 420 relative to the base assembly 410. Such motors could be configured to allow the movement of the assembly in a remote fashion, using wired or wireless transmitters. Example embodiments include motors that could be directed by a program that receives feedback regarding patient input, and directs the assembly to move to counteract such patient movement. It should be noted that the operation of such motors could be via a remote control device or local operation. Wireless or wired control could be utilized to move the system. Wireless control could be via WiFi or cellular or Bluetooth Low Energy systems, or any number of other communication mechanisms.

Referring again to FIG. 8 , as the overall system is designed to direct beams of energy, as shown in FIG. 1 , to its intended target, through the floating scanning assembly 440 and the lens portion 420. Any movement of the floating scanning assembly 440 and objective lens assembly 420 relative to the base assembly and potentially the source of the beam must be compensated for. An arrangement of mirrors can be used, in certain example embodiments, to direct such an energy beam into the floating scanning assembly 440 and objective lens assembly 420 no matter where in the floating scanning assembly 440 and objective lens assembly 420 are, relative to the base assembly 410. Thus, the mirrors could be arranged to move to keep the beam directed into the floating scanning assembly 440 and objective lens assembly 420 or be fixed to the various portions of the base assembly 410 in order to maintain the beam direction into the floating scanning assembly 440 and objective lens assembly 420. Such a beam source, such as a laser, could be mounted to the base assembly or some other structure attached to or nearby the base assembly. Any kind of system could be used, as described in U.S. application Ser. No. 14/191,095 Laser Eye Surgery Systems or other such systems.

The horizontal y axis fixed mirror 450 works in conjunction with the horizontal y axis floating mirror and x axis fixed mirror 452. Finally, the horizontal x axis floating mirror, and the vertical z axis fixed mirror 454 direct the beam into the floating scanning assembly 440 and lens portion 420. These mirrors keep the energy beam aimed at the floating scanning assembly 440 and lens assembly 420, no matter where the floating scanning assembly 440 and objective lens assembly 420 is moved on its three axis bearing system, relative to the base assembly 410.

It should also be noted that the bearings, springs and mirrors are shown in representative places on the base assembly 410 of the assembly. These components could be moved to other parts of the base assembly 410, oriented in different ways than are shown in the example of FIG. 8 . Additional mirrors could be used, for example in embodiments with more than three degrees of freedom.

In certain example embodiments, a patient support structure, such as for example a bed or gurney support, could be coupled to the base assembly 410 or base assembly support structure and be used to accommodate for patient movement relative to the system such as that discussed in FIGS. 3, 4, 5 and 6A. An arrangement of motors in communication with a computer that can sense patient movement, provide a feedback loop and move the patient support structure accordingly, to compensate and keep the patient in place of the energy beam coming through the floating scanning assembly 440 and objective lens assembly 420. Such a patient support structure could also be moved manually or through direction of a user into such motors.

CONCLUSION

Other variations are within the spirit of the present invention. Thus, while the invention is susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof are shown in the drawings and have been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. 

What is claimed is:
 1. A method for performing a laser eye surgery on a patient's eye, comprising: directing a laser beam generated by a laser beam source from a base assembly along a variable optical path into an optical scanning assembly; coupling the optical scanning assembly to the eye via a patient interface device; by a microelectromechanical force sensor, measuring a force on the eye by the patient interface device and converting the measured force into an electrical signal with a response time of tens of microseconds, the microelectromechanical force sensor being preloaded in a compression state; by the optical scanning assembly, scanning a focal point of the laser beam in at least two dimensions to different locations within the eye; receiving a portion of the laser beam which has been reflected from the focal point back along the variable optical path, with a sensor and generating an intensity signal indicative of the intensity of the portion of the laser beam; wherein the variable optical path has at least two mirrors configured to translate relative to each other, wherein the optical scanning assembly is mounted to the base assembly via: a horizontal x axis linear bearing, configured to support a translation movement of the optical scanning assembly in an x axis direction; a horizontal y axis linear bearing, configured to support a translation movement of the optical scanning assembly in a y axis direction; a vertical z axis linear bearing, configured to support a translation movement of the optical scanning assembly in a z axis direction; and a vertical z axis spring, configured to counteract the forces of gravity on the optical scanning assembly in the vertical z axis, and by a plurality of motors attached to the bearings, and based on the electrical signal from the microelectromechanical force sensor, actuating movements of the optical scanning assembly in the x, y and z axis directions relative to the base assembly; and freely following a movement of the patient's eye relative to the base assembly in the x, y and z directions along the variable optical path with the optical scanning assembly and the patient interface device.
 2. The method of claim 1, wherein each of the horizontal x axis linear bearing, the horizontal y axis linear bearing and the vertical z axis linear bearing is a roller and rail bearing and the vertical z axis spring includes a pair of coiled metal tapes each coiled around a spring loaded spool.
 3. The method of claim 1, wherein the optical scanning assembly includes a confocal lens assembly.
 4. The method of claim 1, further comprising: accommodating relative movement between the base assembly and a patient support bed or gurney, the patient support bed or gurney being able to support a patient. 